In summary, our longitudinal data with measurement of BMI at 3.5, 7 and 11 years of age, confirm that several of the adult obesity risk gene variants (ADIPOR2, BCDIN3D_FAIM2, BDNF, CTNNBL1, FTO, HMGA2 KCTD15, MTMR9 MC4R, PTER, SEC16B, and SH2B1) were also associated with childhood growth in New Zealand. The gene discussed is KCTD15; the disease is obesity due to melanocortin 4 receptor deficiency.